Apache2

als Webserver verwenden wir Apache2 mit PHP4, mod_security, mod_auth_pam, mod_deflate. Desweiteren lassen wir die Logfiles nach einem Tag rotieren. Rotiert wird nach UTC, d.h. wir müssen eine Stunde wieder abziehen (-60).

Multihome-Umgebung

In einer Multihome-Umgebung laufen z.b. mehrere verschiedene Domains/Apache-Prozesse auf einem Server. Diese Domains haben aber überhaupt nichts miteinander zu tun. D. h. wiederrum, daß die Domains bzw. der User, die dahinter stehen, natürlich auch kein Zugriff auf die jeweiligen Dateien der andere Domains haben. Gleiches gilt natürlich für den Apache-Prozess! Als Apache-Worker-Modul wird apache2-mpm-itk verwendet.

Für die technische Umsetzung bedeutet das folgendes:

• Optional: Jede Domain hat eine eigenen User/Gruppe (der User ist nicht in seiner eigene Gruppe!, der User bekommt nur r-Rechte, die Gruppe rw-Rechte. In dieser Gruppe muß auch der User sein, der die Seiten der Website pflegt.)
  

conf.d/myconfig

LogFormat "%v %h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"" vcombined
# global access log
CustomLog "|| /usr/sbin/vlogger -s access.log -t access.log.%Y.%m -u ${APACHE_RUN_USER} -g ${APACHE_RUN_GROUP} ${APACHE_LOG_DIR}/vlogger" vcombined

UseCanonicalName Off

conf.d/security

<Directory />
        AllowOverride None
        Order Deny,Allow
        Deny from all
</Directory>


ServerTokens Prod


ServerSignature Off

virt. Host

bsp site-conf /etc/apache2/sites-available/xxxtemplate:

Listen 62.146.xxx.xxx:80
<VirtualHost 62.146.xxx.xxx:80>
       ServerAdmin webmaster@xxx
       ServerName xxxx
       ServerAlias www.xxxx2
       DocumentRoot /home/www/xxxx/htdocs
       <Directory />
               Options FollowSymLinks
               AllowOverride None
       </Directory>
       ErrorLog "||/usr/sbin/rotatelogs -l /home/www/xxxx/logs/error.log.%Y.%m.%d 86400"
       # Possible values include: debug, info, notice, warn, error, crit,
       # alert, emerg.
       LogLevel warn

       #we use global vlogger, so disable
       #CustomLog "|/usr/sbin/rotatelogs /home/www/xxxx/logs/access.log.%Y.%m.%d 86400 -60" combined
</VirtualHost>

Module

Verzeichnisschutz

mod_auth_pam

Für den Verzeichnisschutz verwenden wir mod_auth_pam, d.h. wir können die gleichen Logindaten wie am System nutzen. Damit man eine Gruppe nutzen kann, wird libapache2-mod-auth-sys-group benötigt!

eine bsp. .htaccess:

AuthPAM_Enabled on
AuthType Basic
AuthName "secure area"
require group staff

Falls es nicht geht, vom error.log:

[error] [client 217.229.133.31] PAM: user 'xyz' - not authenticated: Authentication failure

Der User www-data muß Mitglied der Gruppe shadow sein!

mod-auth-imap

Source: http://ben.brillat.net/projects/mod_auth_imap/
kleines Howto: https://hw.cs.southern.edu/prot/mod_auth_imap.htm

Patch for dovecot:  http://srteam.skyrock.com/2121064465-mod-auth-imap2-et-dovecot-le-patch.html or you get

mod_auth_imap: Premature server disconnect for user xxx
mod_auth_imap: Server said: * CAPABILITY ...

--- mod_auth_imap.c.orig        2006-05-08 01:22:43.000000000 +0200
+++ mod_auth_imap.c     2012-09-24 19:56:27.000000000 +0200
@@ -44,8 +44,6 @@
  
 #define _OK 1
 
-int Sock;
-
 
 /*******************************************************************************
  * tcp_gets
@@ -141,6 +139,7 @@
     char result[512],buf[512];
     int ret=0;
     int port;
+    int Sock; // Don't know why it used to be global, but having it local solved *all* my problems
 
     port=atoi(cport);
 
@@ -164,15 +163,17 @@
     tcp_puts(Sock,buf);
 
     //get the capability line...
-    tcp_gets(Sock,result,500);
+    //tcp_gets(Sock,result,500);
 
     //get the "A001 OK CAPABILITY completed" line..
-    tcp_gets(Sock,result,500);
+    //tcp_gets(Sock,result,500);
 
     //skip lines that start with "*"
-    if (strncmp(result,"* ",2 == 0)) {
+    //if (strncmp(result,"* ",2 == 0)) {
+    do {
        tcp_gets(Sock,result,500);
-    }
+    //}
+    } while (strncmp(result,"* ",2) == 0);
 
     //Verify that it supports the CAPABILITY command
     if (strncmp(result,"A001 OK", 7) != 0) {
@@ -186,7 +187,11 @@
     memset(buf,0,500);
     sprintf(buf,"A002 LOGIN %s \"%s\"\r\n", username, pass);
     tcp_puts(Sock,buf);
-    tcp_gets(Sock,result,500);
+
+    //skip lines that start with "*" (sometimes needed with dovecot)
+    do {
+       tcp_gets(Sock,result,500);
+    } while (strncmp(result,"* ",2) == 0);
 
     if (strncmp(result,"A002 OK",7) == 0) {
         if (logflag) {
@@ -197,7 +202,6 @@
     } else if (strncmp(result,"A002 NO",7) == 0) {
         if (logflag) {
             ap_log_rerror(APLOG_MARK,APLOG_WARNING|APLOG_NOERRNO,0,r,"mod_auth_imap: Login failed for user %s.", user
name);
-            ap_log_rerror(APLOG_MARK,APLOG_WARNING|APLOG_NOERRNO,0,r,"mod_auth_imap: Server said: %s", result);
         }
 
         ret=!_OK;
@@ -205,7 +209,6 @@
         //it must have told us BYE and disconnected
         if (logflag) {
             ap_log_rerror(APLOG_MARK,APLOG_WARNING|APLOG_NOERRNO,0,r,"mod_auth_imap: Premature server disconnect for 
user %s.", username);
-            ap_log_rerror(APLOG_MARK,APLOG_WARNING|APLOG_NOERRNO,0,r,"mod_auth_imap: Server said: %s", result);
         }
 
         ret=!_OK;
@@ -218,11 +221,11 @@
     sprintf(buf,"A003 LOGOUT\r\n");
     tcp_puts(Sock,buf);
 
-    //read the BYE line
-    tcp_gets(Sock,result,500);
+    //read the BYE line, skip lines that start with "*"
+    do {
+        tcp_gets(Sock,result,500);
+    } while (strncmp(result,"* ",2) == 0);
 
-    //read the OK LOGOUT
-    tcp_gets(Sock,result,500);
 
     if (strncmp(result,"A003 OK",7) == 0) {
         if (logflag) {
@@ -233,7 +236,6 @@
     } else {
         if (logflag) {
             ap_log_rerror(APLOG_MARK,APLOG_WARNING|APLOG_NOERRNO,0,r,"mod_auth_imap: Error in logout for %s.", userna
me);
-            ap_log_rerror(APLOG_MARK,APLOG_WARNING|APLOG_NOERRNO,0,r,"mod_auth_imap: Server said: %s", result);
         }
 
         ret=!_OK;

.htaccess

#Turn on IMAP Authentication
Auth_IMAP_Enabled on

#Give a name to the authentication domain, whatever you want:
AuthName "SAU Email username and password"

#Only basic authentication is supported for now:
AuthType Basic

#If you feel like it, restrict the users or allow all valid users:
Require valid-user
#Make IMAP Authentication authoritative for this .htaccess file:
Auth_IMAP_Authoritative on

#Set the IMAP Server to which you want to connect (default=localhost):
Auth_IMAP_Server imap.southern.edu

#Set the port on which the imap server is running (default=143):
Auth_IMAP_Port 143

#Turn on some extra logging (login attempts, etc.) in Apache's Error Log
Auth_IMAP_Log on

mod_security

ModSecurity is an open source, free web application firewall (WAF) Apache module. With over 70% of all attacks now carried out over the web application level, organizations need all the help they can get in making their systems secure. WAFs are deployed to establish an external security layer that increases security, detects and prevents attacks before they reach web applications. It provides protection from a range of attacks against web applications and allows for HTTP traffic monitoring and real-time analysis with little or no changes to existing infrastructure.

Installation http://www.thefanclub.co.za/how-to/how-install-apache2-modsecurity-and-modevasive-ubuntu-1204-lts-server

#/etc/modsecurity/modsecurity.conf

SecRuleEngine On

SecRequestBodyLimit 16384000
SecRequestBodyInMemoryLimit 16384000

cd /etc/modsecurity
mv /etc/modsecurity/modsecurity.conf-recommended /etc/modsecurity/modsecurity.conf
mkdir activated_rules activated_optional_rules
ln -s /usr/share/modsecurity-crs/base_rules base_rules
ln -s /usr/share/modsecurity-crs/optional_rules/ optional_rules
cd base_rules
for f in `ls *` ; do ln -s /etc/modsecurity/base_rules/$f /etc/modsecurity/activated_rules/$f ; done
cd ..

cd optional_rules
for f in `ls *` ; do ln -s /etc/modsecurity/optional_rules/$f /etc/modsecurity/activated_optional_rules/$f ; done
cd ..

ln -s /usr/share/modsecurity-crs/modsecurity_crs_10_config.conf

#/etc/apache2/mods-available/mod-security.conf
...
        Include "/etc/modsecurity/*.conf"
        Include "/etc/modsecurity/activated_rules/*.conf"
        Include "/etc/modsecurity/activated_optional_rules/*.conf"
...

Für bestimmte Verzeichnisse kann man den Filter auch ausstellen:

 <Location /upload.php>
    # Do not inherit filters from the parent folder
    SecFilterInheritance Off
 </Location>

Virus-Scanner for uploaded files

#in modsecurity_crs_46_av_scanning.conf
#
# Modify the operator to use the correct AV scanning script/tool
# Example tools are in the util directory.
#

SecRule FILES_TMPNAMES "@inspectFile /usr/bin/runAV.pl" \
        "phase:2,t:none,block,msg:'Virus found in uploaded file',id:'950115',tag:'MALICIOUS_SOFTWARE/VIRUS',tag:'PCI/5.1',severity:'2',setvar:tx.anomaly_score=+%{tx.critical_anomaly_score},setvar:tx.%{rule.id}-MALICIOUS_SOFTWARE/VIRUS-%{matched_var_name}=%{tx.0}"

Web Services using Mod Security (Apache) Methodology and Filtering Techniques by Shreeraj Shah on 19/01/05

http://www.gotroot.com/mod_security+rules

Die Apache-Firewall: Web-Server mit mod_security absichern

mod_php

see PHP

mod_dav

WEBDAV-Modul für Apache. Damit ist es möglich Dateien über https zu manipulieren (ändern, löschen, erstellen usw.). installieren: a2enmod dav

#httpd.conf 
 Alias /phparea /home/gstein/php_files
 Alias /php-source /home/gstein/php_files
 DavLockDB /tmp/DavLock.myvhost
 <Location /php-source>
  Dav On
  AuthType Basic
  AuthName DAV
  AuthPAM_Enabled on
  require group staff
  php_flag engine off # oder  ForceType text/plain
 </Location>

mod_evasive

mod_evasive is an evasive maneuvers module for Apache to provide evasive action in the event of an HTTP DoS or DDoS attack or brute force attack. It is also designed to be a detection and network management tool, and can be easily configured to talk to ipchains, firewalls, routers, and etcetera. mod_evasive presently reports abuses via email and syslog facilities.

Detection is performed by creating an internal dynamic hash table of IP Addresses and URIs, and denying any single IP address from any of the following:

• Requesting the same page more than a few times per second
• Making more than 50 concurrent requests on the same child per second
• Making any requests while temporarily blacklisted (on a blocking list)

<IfModule mod_evasive.c>
  #DOSHashTableSize gibt die Größe der Hashtabelle in Bytes an
  DOSHashTableSize 3097

  #DOSPageCount gibt die Anzahl der Seitenaufrufe eines Clients pro DOSPageInterval-Zeitintervall
  DOSPageCount 2

  #DOSSiteCount gibt die Anzahl der Seitenaufrufe auf einen Child-Prozess pro DOSSiteInterval-Zeitintervall
  DOSSiteCount 50

  #DOSPageInterval und DOSSiteInterval werden in Sekunden angegeben
  DOSPageInterval 1
  DOSSiteInterval 1

  #DOSBlockingPeriod gibt die Sperrzeit in Seknunden an
  DOSBlockingPeriod 60

  #DOSEmailNotify gibts die eMail Adresse an, an welche eine Warnmail geschickt wird
  DOSEmailNotify admin@mydomain.net

  #DOSSystemCommand führt bei einem Angriff weitere Programme/Scripte aus wenn gewünscht
  #DOSSystemCommand "su - someuser -c '/sbin/... %s ...'"

  #DOSLogDir gibt das Verzeichnis an in dem das Modul seine Logfiles schreibt
  DOSLogDir /srv/www/vlogger/_mod_evasive

  #DOSWhitelist beinhaltet eine Aufzählung aller IP-Adressen für die mod_evasive NICHT gilt
  DOSWhitelist 127.0.0.1
</IfModule>

mod_cband

Bandbreiten-Beschränkung http://nodomain.cc/archives/2007/01/05/684-Apache2-Zugriffskontrolle-mit-mod_cband.html

mod_ssl

Disable SSLv2, from http://aruljohn.com/info/sslversion/

#/etc/apache2/mods-available/ssl.conf
SSLProtocol all -SSLv2
SSLCipherSuite ALL:!aNULL:!ADH:!DH:!EDH:!eNULL:!LOW:!MEDIUM:!EXP:RC4+RSA:+HIGH

Links

http://httpd.apache.org/docs/2.0/programs/rotatelogs.html
http://www.php-accelerator.co.uk/
PHPACA Web Front End
http://www.modsecurity.org/
http://www.nuclearelephant.com/projects/mod_evasive/
Speed Up Sites with htaccess Caching